The Needs Addressed
In the past decade or two, it has become increasingly common to construct new athletic stadia and the like with enclosing domes so that such stadia can be used for desired purposes without regard to local weather conditions. One of the first such large enclosed stadia in the Astrodome in Houston, Tex. The enclosing dome of that stadium has a conventional roofing system, with local support members, placed over a complex primary supporting truss and girder network which is of conventional nature. The erection of the enclosing dome of the Astrodome required extensive use of expensive shoring erected on the stadium floor. Maintenance of that dome often requires the use of scaffolding, but in any event is periodically required and is expensive. Today, at least in some areas, the construction of a stadium dome of the kind found in the Astrodome would be prohibitively expensive.
Also, there now exist through the world many stadia and the like which are now not covered or enclosed, but which could benefit significantly by being covered or enclosed. These stadia were not originally designed to support covering roof structures. Such stadia are frequently used for sporting events and the like. If such a stadium is to be covered or enclosed, it is desirable that the enclosing roof or dome structure be light in weight and be capable of being erected rapidly without the use of shoring, the presence of which interferes with use of the stadium. It is also desirable that the loads of the dome, and of loads applied to the dome, be carried in ways which do not require major and costly modifications of the existing stadium structure.
The foregoing circumstances establish that a need exists for advanced large clear-span domes which are light in weight and structurally efficient in terms of ability to support their own weight and applied loads and in terms of carrying such loads to supporting foundations, which can be erected without the use of major shoring, which upon completion require minimum maintenance, and which are so structured that such maintenance as is required can be accomplished economically. A structurally efficient dome requires a minimum number of supporting foundations, and such foundations as are required should be simple and aesthetically pleasing. The dome structure preferably should be adaptable to existing stadia which present different perimetral configurations of spaces to be enclosed, rather than itself dictating or limiting the geometry of the space to be enclosed.